The Ultimate Guide to Caring for a Cast Iron Plant

If you want a plant that’s hard to kill, the cast iron plant (Aspidistra elatior) is pretty much your best bet. These hardy, flowering plants hail from Japan and Taiwan and are also called bar room plants. Named for their ability to survive in many conditions, cast iron plants can grow in low-light areas and with little water.

“These plants can tolerate a wide variety of neglect ranging from poor light and infrequent watering to low humidity and temperature fluctuations,” says Brock Ingham, experienced gardener and owner of Bigger Garden. “If you’ve ever come home from a short vacation to find your houseplants wilted and looking sad, cast iron plants may be the right variety for you.”

We recommend adding this plant baby to your collection for its bright green foliage, no matter your skill level though. Here's how to care for a cast iron plant so it thrives.

Characteristics

These resilient evergreen plants grow 2 to 3 feet high and 1 to 2 feet wide. Cast iron plants have long, stiff, pointed green leaves, and some have yellow and white speckles or light-colored stripes. 

Growing Conditions

Light

Cast iron plants do best with indirect light in low-lit indoor or outdoor areas. They can be damaged by direct sunlight, which can burn their leaves. If you have outdoor cast iron plants, ensure they’re in shady places and not exposed to direct sunlight. 

“Cast iron plants have a preference for low to moderate, indirect light, making them an ideal choice for indoor environments that may not be flooded with natural light,” Ingham says. “While they excel in low-light areas, it’s crucial to shield them from direct sunlight, as intense exposure can damage their leaves.”

Water

To keep cast iron plants healthy, allow them to dry out between waterings. Do not let their pots sit in trays of excess water. Overwatering can lead to root rot, the main risk for these otherwise resilient plants. 

Anna Ohler, owner of Bright Lane Gardens Nursery, says, “These hardy plants can go without water for extended periods, making them ideal for new or distracted gardeners.” 

Temperature and Humidity

Ohler says cast iron plants should be kept in temperatures between 50 and 80 degrees Fahrenheit. Although they are tough plants, cold temperatures can damage or kill them, so they should not be kept below 50 degrees. 

Cast iron plants do well in average humidity. The hardy evergreens can grow well in most humidity levels, but if your home is particularly dry, a humidifier might be helpful. 

Soil

Regular potting soil or mixes designed for succulents or cacti can work well for cast iron plants. Cast iron plants grow well with a mildly acidic to neutral pH. They are flexible and can grow in soil with a pH between 5.5 and 7.5.

“While standard houseplant mixes are suitable, mixes designed for succulents or cacti will add the extra drainage needed for them to thrive,” Ingham says. “The goal is to provide a soil environment that supports moisture retention without retaining excess water, thus preventing the roots from sitting in water."

Fertilizer

Fertilize your indoor cast iron plants with liquid fertilizer once a month during the spring and summer. You do not need to fertilize them in the fall and winter months. For outdoor cast iron plants, give them an all-purpose fertilizer once a year in the spring or summer.

Common Pests and Diseases

Cast iron plants are resistant to many common pests and problems, especially when grown outdoors in their natural environment, but they're not impervious. See below for common issues people face with cast iron plants.

Root Rot

Root rot is one of the most common issues for cast iron plants. You can ward off root rot by planting your cast iron plants in well-draining soil and avoiding overwatering them. 

“​​Root rot is the primary disease concern for cast iron plants, usually resulting from overwatering,” Ingham says. “This condition can lead to the decay of the roots, eventually harming the entire plant. If root rot occurs, it may be necessary to repot the plant in fresh soil after removing any decayed roots.”

Brown Leaves

Cast iron plants can develop brown leaf tips from over-fertilization, low humidity, or overwatering. Allow your plant soil to dry out between waterings and use filtered water or rainwater if you have harsh tap water, Ingham advises. If you have dry air in your home, you can increase humidity with a humidifier. 

Bleached Leaves

Another risk cast iron plants face is from direct sun exposure. If your cast iron plant’s leaves look bleached, your plant may be getting too much sunlight. Make sure your cast iron plants are out of direct sunlight to ensure healthy leaves. 

Pests

Sometimes, indoor cast iron plants fall prey to pests such as scale, mealy bugs, and spider mites. If any of these pests attack your plants, spray your plants with warm water to knock the pests off. If you have an infestation, use insecticidal soap or horticultural oil to eliminate the pests. 

Are Cast Iron Plants Toxic?

Nope! They are not toxic. Cast iron plants are totally safe to keep out around dogs, cats, and small kiddos.